ADSORPTIVE STRIPPING VOLTAMMETRIC BEHAVIOR OF HYPOXANTHINE

The effective adsorption of hypoxanthine at a hanging mercury drop ele ctrode (HMDE) has been studied by using ac and cyclic voltammetry (CV) . It was found that the complexation of hypoxanthine molecules enhance s the stacking interactions which might facilitate the formation of a perpendicularly stacked layer of Cu(II)-hypoxanthine complex on the el ectrode surface. A rapid and sensitive controlled adsorptive accumulat ion of copper complexes with hypoxanthine on the HMDE provides the bas is for the direct stripping measurement of this compound on the subnan omolar concentration level. The height of the chelate peak is shown to be proportional to the hypoxanthine concentration. Experimental and i nstrumental parameters for the quantitative determination are optimize d. Under optimum conditions the calibration curve was linear and the d etection limit was 1x10(-8) M (1.36 mu g l(-1)), where in the presence of Cu(II) the method is developed and the detection limit is lowered to 3x10(-10) M (0.05 mu gl(-1)). The interferences of several organic compounds are described.